This invention relates to incendiary devices to initiate firebreaks and the like. More particularly it relates to incendiary devices that permit brush fires to be started remotely from the person controlling the device.
Forest and brush fires are major problems for both the communities and firefighters that have to deal with them on a regular basis, such as the western part of the United States. Forest fires can be either controlled or prevented by intentionally igniting fires. As a control mechanism, a fire can be set to burn off accumulated fuel during a season where there is little chance of creating an uncontrolled fire. This is called a controlled burn. The following description is for the control of wild fires, although, similar conditions exist for the controlled burn. For most of these fires, the goal is to gain control as quickly as possible. One technique regularly employed to establish control is the backfire where areas in the fire's path are burned to deprive the fire of fuel thereby creating a buffer zones that impedes the fires. A large variety of devices have been used to start these backfires. A partial list includes matches, electric lighters, hand-thrown devices, fuses, drip torches, plastic bags of gelled fuel, canister devices, pneumatic torches, propane torches, power flame throwers, flare pens, signal pistols, and various launching devices. Launching devices range from compressed air to slingshots.
For a detailed description of all of these devices with warnings about their dangers and limitations, the United States Department of Agriculture, Forest Service, has a detailed book called "Ground Ignition Systems: An Equipment Guide for Prescribed and Wild Fires." In summary all current devices have severe restrictions. Setting a backfire is a race against time. An out of control fire is advancing towards the firefighters in the area of a designated backfire location. The firefighters first have to assure that the fire they are starting will burn in a direction they can control. Next the firefighters have to start the backfire over a large enough area and give it adequate time to burn away from the fire line they have set to define the backfire and towards the fire to be controlled.
In order for the firefighters to burn large areas, it is necessary to first light a small continuous fire adjacent to a trail or road, then launch flares beyond the small fire line. The launched flares produce a fire that will draw the smaller fire line towards it. The combination produces a fire line of considerable width.
In general, state of the art devices have limited fire-starting performance, many are rated as explosives, some of the devices are high cost, and most burn and/or explode easily. Further, they may require supporting devices such as air compressors to be launched. Several of them require a firefighter to take the device to the stage where the fire is to be started. This leads to firefighters walking inside the fire line starting the extension fires. Such activity puts the firefighter at increased personal risk, especially when the terrain is very rough.
Thus the prior techniques required coordination of equipment, protection of explosive/combustive materials in the midst of a fire area, and the time of assuring fires were started along a fire line an adequate time.